Copying-pad



or OALIFOBN corms-PAD. 1,348,812. Specification 01' Letters Patent. Patented Aug, 3, 1920' No Drawing Q Application filed December}, 1919. SerialNo. 342,499.

To all tckom it may concern.

' Be it known that I, LOUIS V. LANDAU, a Jo citlzen of the United State, residing at Los Angeles, in and State of California, have invented new and useful Improvements in Copying-Pads,

. of which the followingis a'specification:

' in the. center necessary toavoid bringing tated until a h y invention relates to a composition for copying pa'dsand has for its object to provide a copying pad which is inexpensive of construction and capable of maklng copies, of printed or ink, whether prllnting, writing or hectographic ink of any co or.

My invention consists in the new compo sition hereinafter described and claimed, and which is compounded as follows:

- 3% kgs. of glycerin,

6 kgs. ofkaolin,

5O grs. sodium carbonate, 80 grs. barium sulfate,

250 grs. dextrin. he composition is compounded inthe following manner: The kaolin is laced in a suitable receptacle and a cavity 1s formed; of the mass of kaolin, for a. purpose presently tobe gently heated, then the' extrin, sodium carbonate and barium sulfate is added and the temperature raised to about 150 F. Itis the mixture to a boil lest destructive reactions occur. With a suitable stirring device'the mixture is agiomogeneous mass is formed. The mixture in' pared as justescribed, ISJIQW placed into the first receptaclecontainingthe kaolin and into the cavity formed them, and "with a suitable stirnng device the kaolin is incorporated in the mixture of glycerin, dextrin, sodium carbonate and barium sulfate until the mass is homogeneous.

-he mass is now spread upon a'table in a Y thin layer and exposed to the atmosphere for a day or two. he composition is of the consistency and. color of putty and has a granular texture.

he composition is now ready to be used for the copying pad'which may consist of afshallow frame having a flat bottom and {Side walls of small dimensions. The compothe county of Los Angeles written matter made by means of any commercial copying :my composition in-the described. jlnto 3 another receptacle the l cerin is placed and Y ject of the second receptacle, re-

. be 'made without departing 1. A composition for making cop es of printed or wrltten mat- 0 'n, glycerin, barium sul- In making a copy from the sheet printed or written with copying ink, or copying pencils, of various colors, it is merely necessary to place the sheet with the printed face downward on the copying pad and press the same firmly against the pad by means of 1 a roller or mallet and remove the printed sheet, when the copying pad will now have an imprint of the printed or written sheet. A blank piece of paper is now placed on the copying pad and suitable pressure exerted thereon. On removing the sheet of papera copy of the printed matter will appear on the. same. any copies -may .be made from the same or imprints I copies that are taken from the copying pad.

To restore the copying pad for the next operation it is merely necessary sponge to wipe off the imprint. I I. d it advisable to add crude rubberwto proportion of about of, the whole mass, and thoroughly lmeadgandagitate. the mass by any suitable machinery until the rubber is thoroughly disseminated throughout the mass and forms to use a wet a 'homogeneous mixture therewith. The

composition seems to have solvent roperties to 'softenand dissolve the rubber during the agitation referred the rubber is to cause the copying 1 pad to last longer and resist wear.

The crude rubber is'not absolutely essential and may h e omitted. j

T It is understood that various changes may of my invention as claimed.-

claim:

ter, comprismgka fate and dextrin.

composition for a copying pad for making copies of printed or written matter,

comprising the followin proportions stated: kao 1n 6 kgs.,-glyceri n 3 kgs., sodium carbonate 50 grs., barium sulfate grs, and dextrin 250 grs.

ingredients in the to. The obfrom the spi'rlt a copying pad for as V 3. A composition for a copying pad for proportions stated: kaolin 6 kgs., glycerin making copies of printed or'written mat- 3% kgs., sodium carbonate 50 grs., barium ter, comprising kao lin, glycerin, barium sulfate 80 grs., dextrin 250 grs., and rubber 10 sulfate, dextrin and rubber. about 3% of. the whole mass.

5 4:. A compos'tion for a copyingpad for In testimony whereof 'I'have signed my. making copies of printed or'written matter, name to this specification. comprlsing the fo1lowing' ingredients in the Y LOUIS V.- LANDAU. 

